This invention relates to an electrical connection and is particularly concerned with an electrical connection to conductive materials that can serve the purpose of a heating means.
It has long been known that materials that are electrically conductive can generate heat. This phenomenon has spawned a considerable number of heating means for a considerable number of different purposes.
Whilst electrical heaters at large are generally successful, and more than capable of meeting their intended purpose, what has proved to be difficult, is the achieving of a uniform heating effect over a relatively wide area, substantially free from hot and cold spots or areas.
There have been attempts hitherto to create electrical heaters in sheet or web form to serve a wide variety of purposes. However, the most usable form of conductive material is in the form of carbon particles or carbon black embedded in or coated on a carrier or substrate. To attempt to achieve a uniform heating effect, a greater density or concentration of carbon particles is employed, but as a direct result of that, the material becomes less pliable and more brittle, to the detriment of the employment of the material over a wide range of potential uses.
In U.S. patent application Ser. No. 09/857,241 of which the present Application is a continuation-in-part, there is described and claimed a flexible electrically heatable semi-conductive material able to be used in a variety of different physical forms to suit a wide variety of electrical conduction heaters, with a substantially constant and controllable heating effect over the full length and width of the heatable material.
The preparation of the said conductive material and the manner of its application to a carrier is such that a visually smooth coating or film is provided. However, it remains so that the coating or film will exhibit a microscopic degree of roughness with peaks and troughs formed by carbon particles at the exposed surface. It is then important to pay special attention to the provision of an electrical connection to the coat or film.